tilegame.cpp

tilegame.cpp

#include <cstdlib>
#include <iostream>
#include <cmath>

using namespace std;

int checkCompletion(int pos[3][3]);
int dist(int num, int x, int y);
int bestTile(int tiles[3][3], int & x, int & y);
void printBoard(int tiles[3][3]);
void cloneBoard(int board[3][3]);

/*
  Returns a number. The closer to zero this number is, the more complete the
  puzzle is. If the value of this number is zero, the puzzle is complete.
*/
int checkCompletion(int pos[3][3])
{
    int total = 0;
    for(int x=0;x<3;x++)
    {
            for(int y=0;y<3;y++)
            {
                    if(pos[x][y]<0)
                                   continue;
                    total += dist(pos[x][y], x, y);
            }
    }
    return total;
}
/*
  Determine the physical number of moves required to put a piece back where it
  needs to be.
*/
int dist(int num, int x, int y)
{
    int sXpos = 0, sYpos = 0; // The vars that will store where the num is
    
    sXpos = ((num-1) % 3);
    sYpos = ((num-1) / 3);
    
    return abs(x - sXpos) + abs(y - sYpos);
    
}
/*
  Determines the best tile to move.
*/
int bestTile(int tiles[3][3], int & x, int & y)
{
     int bestX = -1, bestY = -1, bestDist = 0, curDist = 0, potentialDist = 0;
     int px, py;
     
     py = 0;
     for(px=-1;px<=1;px+=2)
     {
          if(px + x < 0 || px + x > 2)
              continue;
          curDist = dist(tiles[y][px + x], px + x, y);
          potentialDist = dist(tiles[y][px + x], x, y);
          if(curDist-potentialDist<=0)
          {
              int tempBoard[3][3];
              int tx,ty;
              for(int ti=0;ti<3;ti++)
                  for(int tj=0;tj<3;tj++)
                      tempBoard[ti][tj] = tiles[ti][tj];
              tempBoard[y][x] = tiles[y][px + x];
              tempBoard[y][px + x] = -1;
              tx = px+x;
              ty = y;
              curDist = bestTile(tiles, tx, ty);
          }
          if(curDist > bestDist)
          {
             bestX = px + x;
             bestY = y;
             bestDist = curDist;
          }
     }
     
     px = 0;
     for(py=-1;py<=1;py+=2)
     {
          if(py+y<0||py+y>2)
              continue;
          curDist = dist(tiles[y][px + x], x, py + y);
          potentialDist = dist(tiles[py + y][x], x, y);
          if(curDist-potentialDist<=0)
          {
              int tempBoard[3][3];
              int ty, tx;
              for(int ti=0;ti<3;ti++)
                  for(int tj=0;tj<3;tj++)
                      tempBoard[ti][tj] = tiles[ti][tj];
              tempBoard[y][x] = tiles[py + y][x];
              tempBoard[py + y][x] = -1;
              ty = py + y;
              tx = x;
              curDist = bestTile(tiles, tx, ty);
          }
          if(curDist > bestDist)
          {
              bestX = x;
              bestY = py + y;
              bestDist = curDist;
          }
     }
     x = bestX;
     y = bestY;
     return bestDist;
}
/*
  Prints the game board to the screen.
*/
void printBoard(int tiles[3][3])
{
     cout << endl << "-----" << endl;
     for(int i=0;i<3;i++)
     {
         for(int j=0;j<3;j++)
         {
             if(tiles[i][j]==-1)
                 cout << "  ";
             else
                 cout << tiles[i][j] << " ";
         }
         cout << endl;
     }
     cout << "-----" << endl;
}

int main(int argc, char *argv[])
{
    int i[3][3] =
    {
        {1, 3, 6},
        {4, -1, 7},
        {2, 5, 8}
    };
    int x=1, y=1;
    
    cout << bestTile(i,x,y) << endl;
    
    printBoard(i);
    
    system("PAUSE");
    return EXIT_SUCCESS;
}